Steel truss



F. G. BORG STEEL TRUSS Sept. 4, 1923.

Filed March 14. 1921 2 Sheets-Sheet 1 v INVENTOR. ED. 6. 5015's,

I" I I p ATTORNEY F. G. BORG STEEL TRUSS' Sept. 4, 1923.

Filed March 14 1921 2 Sheets-Sheet 2 INVEN TOR.

ATTOEY Patented Sept. 4,- 1923.

UNITED s'r'rss Are FREDRIK G. BORG, OF CHICAGO, ILLINOIS.

STEEL TRUSS.

Application filed March 14, 1921. Serial No. &52,290.

To all whom 2'2, may concern:

Be it known that I, FREDRIK G. Bone, a citizen of the United States, and resident of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Steel Trusses, of which the following is a specification.

This invention relates to steel trusses.

Broadly stated, the object of the invention is to, provide a steel truss which may be fabricated, in principal part, from available shapes or'sections of commercial steel bars, and which are particularly designed and adapted for supporting the roofs of buildings of relatively wide span.as the roofs of garages and the like-in which it is desired that the floor space shall be unobstructed by pillars, columns and the like.

Buildings of the-kind specified, are lighted to a large extent by means of sky-lights, and the invention has for a further object to provide a truss which will obstruct the pas sage of light only slightly, thereby permitting free access of light from sky-lights to all parts of the building.

Specifically considered, a further object of the invention is to provide a steel truss construction and a system of bracing therefor, whereby the top chord will be'divided into sections, which are supported at their ends by struts or braces interposed between the top and bottom chords, thereby imparting to the different sections of said top chord the load carrying action and charac-- teristics of beams.

Still a further object of the invention is to provide a truss for the purpose specified, which shall be simple in construction which shall possess adequate strength and rigidity for the purpose for Which it is designed, which will be relatively light in weight and inexpensive to fabric-ate, as compared with any truss for a similar purpose of which I have any knowledge.

To effect the foregoing objects, a truss of my invention comprises the various features, combinations of features and details of con structionhereinafter described and claimed.

In the accompanying drawings in which my invention is fully illustrated:

Figure 1 is a sectional view of the roof and upper' portions of the walls of a building showing a truss of my invention as applied in use for supporting said roof.

Figure 2 is an enlarged, fragmentary view end to end.

of the central portion of said truss and of the roof proper.

Figure 3 is an enlarged, fragmentary}:

view, showing the end of. my improved truss together with portions of the side wall and roof of the building, as shown infFigQl.

Figure 4 isan enlarged, 'sectionalview of my improved truss on the line l4: of Fig. 3.

Figure .5 is a sectional view on theline 55 of Fig. 2; and"v Figures 6 and 7 are fragmentary, sectional views on the lines o f and 77, respectively, of Fig. 2. v I

In the accompanying drawings, in whichI have, for the purposes of concrete anddefi nite illustration shown a truss of my invention as applied in use for supporting the roof of a building, A, A, designate the .walls of the building, B the roof'of thebuilding as a whole, which is supported by trusses embodying my invention, one of which, desigi natcd as a whole C. is shown in side elevation in Fig. l of the drawings,

My improved truss comprises a bowed bent on a desiredarc or radius, secured between which are what may be designated girder plates 6. I

' Depending upon the length of the truss,

the angle-bars forming said topchord may be made in a single'length or may COllSlSt of two or more lengths rigidly connected The angle-bars are secured I together to form a substantially T-shaped section, be-

tween the depending flanges of'whichthe I girder plates 6 are secured, said pgirder plates being relatively much wider than the flanges of the angle-bars between which they are secured {and depending at the under side thereof, no partof said girder plates extending above the top sides of said angle; bars. v

In accordance with my 1nvent1on, sald girder plates 6 consist of a plurality of separate, straight-sided sections connected.

together end to end,said sections being. so disposed that theupperedges thereof will can;

form chords subtending arcs of the bowed angle-bars 5. As shown, said girder plates 6 are riveted to the depending flanges of said angle-bars.

The lower chord 2 of my improved truss also preferably consists of angle-bars 7 secured together in such relation that they will form substantially an inverted T-section.

The ends of the top and bottom chords 1 and 2 are rigidly connected by riveting flanges ofthe angle-bars 7 forming the lower chord to opposite sides of the end girder plates 6, as best shown in Fig. 3.

The struts 3 likewise consist of spaced angle-bars 8 secured to opposite sides of the girder plates 6 and to the connected flanges of the angle-bars 7 which form the lower chord 2, said angle-bars 8 being disposed with a flange of each thereof extending at right angles to the plane of the truss.

The diagonal braces 4 consist of flat bars 9 the lower ends of which are riveted or otherwise secured between the connected flanges of the angle-bars 7 forming the lower chord 2, Substantially at the lower ends of the struts 3. and'the upper ends of which are riveted or otherwise secured to the girder plates 6 in close proximity to the upper ends of the struts 3 next adjacent to the struts to which the lowerends of said diagonals 9 are connected, respectively.

As shown. the abutting ends of adjacent sections of the girder plates .6 are connected by means of diagonal bars 9 which are riveted to the sections of the girder plates 6 so that they will overlap the ends of said sections, as best shown at 10, Fig. 2. and by splice plates 11 secured to the sides of said girder plate sections opposite to the sides thereof to which the ends of the diagonal bars 9 are connected.

As shown, the struts 3 extend substantially radially to the top chord 1 and in such position that their upper ends will be connected to sections of the girder plates '6 as close as practicable to the connected ends thereof.

In the preferable construction shown, the angle-bars 8 forming the struts 3, are connected between their ends by flat bars 12 which extend between and are riveted or otherwise connected to the flanges of said angle-bars and to the diagonal bars 9 at their points of intersection. As shown, said bars consist of separate sections the ends of which over-lap and which are continuous between the points of intersection of adjacent sets of diagonals. Said bars 12 will operate, in an obvious manner, to rigidiy connect the angle-bars 8, thereby greatly increasing their strength to resist buckling stresses.

By making the girder plates-.6 in separate. straight-sided sections, all shaping of said girder plates is eliminated, thereby very materially reducing the cost thereof.

A further advantage in making said girder plates 6 and the bracing bars 12 in separate sections is that they may be made from relatively short lengths, which, as is well known, are much cheaper and can be handled much easier than long lengths.

As the invention relates to a construction whereby a beam action will be imparted to different sections of the top chord, I attain the object of the invention by means, of bracing shown, comprising the struts '3 and diagonals 4:, whereby the top chord will .be divided into a series of separate sections the ends of which will be supported by the struts 3 and which, as regards their load carrying action and capacity,will have the actionand characteristics of beams.

As shown, the roof '13 consists of rafters 13 bolted or otherwise rigidly secured directly to the top sides of the top chord 1, to which the joists 14 are toe-nailed or otherwise secured. The roof covering, desig' nated 15, may consist of any suitable roofing material, as dressed and matched lun1 ber. sheet metal or the like, preferably covered with tar-paper or other material, preferably of a character which will render the roof weather-proof and water-tight.

The ends of the trusses C will be built into the walls A, A, preferably resting upon plates 16, whereby the weight sustained by said trusses will be distributed.

An important advantage of my improved truss is that I have practically eliminated all gusset plate for connecting the web members of the truss to the chord members thereof, thereby affecting a further material saving in both material and labor in the cost of the truss.

I claim 1. A steel roof truss comprising a bowed top chord and a bottom chord rigidly connected to each other at their ends, and web members which connect said top and bot tom chords, the top chord comprising flanged members and a girder plate all ,rig idly connected together, said girder plate being secured between said flanged members and comprising a plurality of straight-sided sections secured together end to end, each of said girder sections being substantially coincident with a single panel of the truss,

being wider than the corresponding dimension of said flanged members, and no part thereof extending above the upper side of the top chord. and the flanged members comprising flanges disposed substantially at right angles to the plane of the truss on opposite sides thereof, substantially as described.

2. A steel roof truss as specified in claim 1, in which the web members of the truss comprise struts and diagonals, said struts comprising oppositely disposed flanged members the upper ends of which are connected directly to the girder plate forming part of the top chord closely adjacent to the connected ends of the sections thereof, and the diagonals comprising crossed diagonals arranged between adjacent struts, opposite ends of which are connected directly to the girder plate forming part of the top chord and to the bottom chord losely adjacent to the upper and lower ends of the struts between which they are arranged, respectively,

secured to opposite sides of said girder plates in position to overlap the abutting ends of adjacent sections thereof, substantially as described.

In testimony that I claim the foregoing as my invention, I aflix my signature this 9thday of March, A. D. 1921.

FRED BORG. 

